Density functional theory study on the electronic structure of Monascus dyes as photosensitizer for dye-sensitized solar cells

Abstract

Abstract This work presents a theoretical study of electronic and redox properties of Monascus dyes using DFT and TDDFT with B3LYP/6-31+G(d,p) level. The dye properties in solvent environment were carried out with IEF-PCM(UAKS)/TDDFT/B3LYP/6-31+G(d,p) method. The ground and excited state oxidation potentials as well as electron injection from the dyes to semiconductor TiO 2 are reported. The calculation shows that all of the dyes can potentially be good photosensitizers in DSSC. Their LUMOs lie over the E cb of TiO 2 and their HOMOs lie under the reduction potential energy of the electrolytes ( I − / I 3 − ) corresponding to ability of electron transfer from the dye excited state to TiO 2 and charge regeneration after photooxidation process, respectively.